% V4

a=0.001; %Np

%t = 0:5e-11:1e-8;
%z = 0 %m

t=0;
z = 0:01:1000;

v = 10.*exp(-a.*z)%.*sin(4.*pi.*1e9.*t - 20.*pi.*z)

plot(z, v)

grid on;